LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Rob Herring <robh@kernel.org>
To: Andrey Pronin <apronin@chromium.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
	Peter Huewe <peterhuewe@gmx.de>,
	Marcel Selhorst <tpmdd@selhorst.net>,
	Jason Gunthorpe <jgunthorpe@obsidianresearch.com>,
	tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org,
	Christophe Ricard <christophe.ricard@gmail.com>,
	Pawel Moll <pawel.moll@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Ian Campbell <ijc+devicetree@hellion.org.uk>,
	Kumar Gala <galak@codeaurora.org>,
	devicetree@vger.kernel.org
Subject: Re: [PATCH v2 1/2] tpm: devicetree: document properties for cr50
Date: Wed, 20 Jul 2016 14:03:03 -0500
Message-ID: <20160720190303.GA5620@rob-hp-laptop> (raw)
In-Reply-To: <5274cc806888a709c639e701dad894543885b2c9.1468985673.git.apronin@chromium.org>

On Tue, Jul 19, 2016 at 08:41:24PM -0700, Andrey Pronin wrote:
> Add TPM2.0 PTP FIFO compatible SPI interface for chips with Cr50
> firmware. Several timing-related properties that may differ from
> one firmware version to another are added to devicetree.
> Document these properties.
> 
> Signed-off-by: Andrey Pronin <apronin@chromium.org>
> ---
>  .../devicetree/bindings/security/tpm/cr50_spi.txt  | 32 ++++++++++++++++++++++
>  1 file changed, 32 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/security/tpm/cr50_spi.txt
> 
> diff --git a/Documentation/devicetree/bindings/security/tpm/cr50_spi.txt b/Documentation/devicetree/bindings/security/tpm/cr50_spi.txt
> new file mode 100644
> index 0000000..f212b6b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/security/tpm/cr50_spi.txt
> @@ -0,0 +1,32 @@
> +* H1 Secure Microcontroller with Cr50 Firmware on SPI Bus.
> +
> +H1 Secure Microcontroller running Cr50 firmware provides several
> +functions, including TPM-like functionality. It communicates over
> +SPI using the FIFO protocol described in the PTP Spec, section 6.
> +
> +Required properties:
> +- compatible: Should be "google,cr50".
> +- spi-max-frequency: Maximum SPI frequency.
> +
> +Optional properties:
> +- access-delay-ms: Required delay between subsequent transactions on SPI.

As I mentioned, there may be common properties. It doesn't seem you 
looked, so I did:

- spi-rx-delay-us  - (optional) Microsecond delay after a read transfer.
- spi-tx-delay-us  - (optional) Microsecond delay after a write transfer.

Seems to me setting one or both of these should work for you.

> +- sleep-delay-ms: Time after the last SPI activity, after which the chip
> +  may go to sleep.
> +- wake-start-delay-ms: Time after initiating wake up before the chip is
> +  ready to accept commands over SPI.

I also asked why these 2 can't be hard-coded in the driver?

> +
> +Example:
> +
> +&spi0 {
> +        status = "okay";
> +
> +        cr50@0 {
> +                compatible = "google,cr50";
> +                reg = <0>;
> +                spi-max-frequency = <800000>;
> +
> +                access-delay-ms = <2>;
> +                sleep-delay-ms = <1000>;
> +                wake-start-delay-ms = <60>;
> +        };
> +};
> -- 
> 2.6.6
> 

  reply index

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-15  2:20 [PATCH 0/2] tpm: add driver for cr50 on SPI Andrey Pronin
2016-07-15  2:20 ` [PATCH 1/2] tpm: devicetree: document properties for cr50 Andrey Pronin
2016-07-15  4:05   ` Guenter Roeck
2016-07-15 17:31     ` Andrey Pronin
2016-07-15 18:28       ` Guenter Roeck
2016-07-17 13:28   ` Rob Herring
2016-07-15  2:20 ` [PATCH 2/2] tpm: add driver for cr50 on SPI Andrey Pronin
2016-07-15  3:32   ` Jason Gunthorpe
2016-07-15  3:44     ` Andrey Pronin
2016-07-19 12:55       ` Jarkko Sakkinen
2016-07-20  0:24         ` Andrey Pronin
2016-07-20 17:03           ` Jason Gunthorpe
2016-07-21 18:10             ` Andrey Pronin
2016-07-21 21:00               ` Jason Gunthorpe
2016-07-15  2:28 ` [PATCH 0/2] " Peter Huewe
2016-07-15  2:50   ` Andrey Pronin
2016-07-15  3:28     ` Jason Gunthorpe
2016-07-15 17:15       ` Andrey Pronin
2016-07-19 12:56 ` Jarkko Sakkinen
2016-07-20  3:41 ` [PATCH v2 " Andrey Pronin
2016-07-20  3:41   ` [PATCH v2 1/2] tpm: devicetree: document properties for cr50 Andrey Pronin
2016-07-20 19:03     ` Rob Herring [this message]
2016-07-20 19:49       ` Andrey Pronin
2016-07-20 19:54         ` Jason Gunthorpe
2016-07-27 21:02           ` Andrey Pronin
2016-07-21 21:03         ` Rob Herring
2016-07-27 21:00           ` Andrey Pronin
2016-07-20  3:41   ` [PATCH v2 2/2] tpm: add driver for cr50 on SPI Andrey Pronin
2016-07-25 17:09   ` Aw: [PATCH v2 0/2] " Peter Huewe
2016-07-27 21:12     ` Andrey Pronin
2016-07-28  4:25 ` [PATCH v3 " Andrey Pronin
2016-07-28  4:25   ` [PATCH v3 1/2] tpm: devicetree: document properties for cr50 Andrey Pronin
2016-07-28  4:25   ` [PATCH v3 2/2] tpm: add driver for cr50 on SPI Andrey Pronin
2016-07-28 23:01     ` Dmitry Torokhov
2016-07-28 23:17       ` Jason Gunthorpe
2016-07-29  3:01         ` Andrey Pronin
2016-07-29  1:55 ` [PATCH v4 0/2] " Andrey Pronin
2016-07-29  1:55   ` [PATCH v4 1/2] tpm: devicetree: document properties for cr50 Andrey Pronin
2016-07-29 17:27     ` Jason Gunthorpe
2016-07-29 21:42       ` Rob Herring
2016-08-09 10:08     ` Jarkko Sakkinen
2016-07-29  1:55   ` [PATCH v4 2/2] tpm: add driver for cr50 on SPI Andrey Pronin
2016-08-09 10:20     ` Jarkko Sakkinen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20160720190303.GA5620@rob-hp-laptop \
    --to=robh@kernel.org \
    --cc=apronin@chromium.org \
    --cc=christophe.ricard@gmail.com \
    --cc=devicetree@vger.kernel.org \
    --cc=galak@codeaurora.org \
    --cc=ijc+devicetree@hellion.org.uk \
    --cc=jarkko.sakkinen@linux.intel.com \
    --cc=jgunthorpe@obsidianresearch.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=pawel.moll@arm.com \
    --cc=peterhuewe@gmx.de \
    --cc=tpmdd-devel@lists.sourceforge.net \
    --cc=tpmdd@selhorst.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git
	git clone --mirror https://lore.kernel.org/lkml/8 lkml/git/8.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git